1. Field of the Invention
The present invention relates to microfilm cameras and particularly to a microfilm camera capable of photographing successively on a microfilm a large number of originals set in a photographing position.
2. Description of the Related Art
In general, a microfilm camera photographs an original when a photographing switch is turned on after the original has been set in a photographing position on a document platen. After an end of photographing of an original, another original is set in the photographing position and thus photographing operation is performed successively.
Such photographing operation involves disadvantages as described below.
It happens that photographing is interrupted after an original has been set. In such a case, it is sometimes unclear whether the set original has been photographed or not after the interruption.
In an electrophotographic copying apparatus or the like, whether the original has been copied or not can be confirmed readily by checking the copy obtained. However, in a conventional microfilm camera, it can be confirmed only after development of the film whether an original has been photographed or not. In addition, the same original is photographed repeatedly by mistake due to uncertain memory of the operator or errors such as failure to photograph an original occur.
Japanese Patent Laying-Open Gazette No. 164730/1982 discloses the following technique.
According to this gazette, a microfilm camera comprises a memory device for successively storing operations of various operation switches, and a switch for reading the contents of this memory device. When it becomes necessary for the operator to confirm whether an original has been photographed or not, the contents of the memory device are successively read out by operation of the reading switch.
However, the technique disclosed in the above indicated gazette involves disadvantages as described below. When the operator desires such confirmation, it is necessary for the operator to operate the reading switch. Thus, any operation by the operator is required. On the other hand, if photographing operation is carried out with no original being set, the fact of turn-on of the photographing switch is recorded. Although it is confirmed by using the reading switch that the photographing operation has been done, it might be erroneously determined by this confirmation that an original has been photographed. Thus, errors in photographing such as failure to photograph an original would occur.